Al-Qaeda's top spiritual leader Anwar al-Awlaki's killing in a drone strike in Yemen could provide motivation for anti-American attacks globally by those seeking to avenge his death, the State Departm

Anwar al-Awlaki, the public face of al Qaeda in the Arabian Peninsula, was killed on Friday in an airstrike in Yemen, dealing another body-blow to the terror network after the death of Osama bin Laden